Today, you will load a filtered gapminder dataset - with a subset of data on global development from 1952 - 2007 in increments of 5 years - to capture the period between the Second World War and the Global Financial Crisis.
Your task: Explore the data and visualise it in both static and animated ways, providing answers and solutions to 7 questions/tasks below.
First, start with installing the relevant packages âtidyverseâ, âgganimateâ, and âgapminderâ.
First, see which specific years are actually represented in the dataset and what variables are being recorded for each country. Note that when you run the cell below, Rmarkdown will give you two results - one for each line - that you can flip between.
unique(gapminder$year)
## [1] 1952 1957 1962 1967 1972 1977 1982 1987 1992 1997 2002 2007
head(gapminder)
## # A tibble: 6 x 6
## country continent year lifeExp pop gdpPercap
## <fct> <fct> <int> <dbl> <int> <dbl>
## 1 Afghanistan Asia 1952 28.8 8425333 779.
## 2 Afghanistan Asia 1957 30.3 9240934 821.
## 3 Afghanistan Asia 1962 32.0 10267083 853.
## 4 Afghanistan Asia 1967 34.0 11537966 836.
## 5 Afghanistan Asia 1972 36.1 13079460 740.
## 6 Afghanistan Asia 1977 38.4 14880372 786.
The dataset contains information on each country in the sampled year, its continent, life expectancy, population, and GDP per capita.
Letâs plot all the countries in 1952.
theme_set(theme_bw()) # set theme to white background for better visibility
ggplot(subset(gapminder, year == 1952), aes(gdpPercap, lifeExp, size = pop)) +
geom_point() +
scale_x_log10()
We see an interesting spread with an outlier to the right. Answer the following questions, please:
Q1. Why does it make sense to have a log10 scale on x axis? Becasue the variable âgdpPercapâ contains hard skewness, meaning that some values are very large, log10 allows us to get a better view of the data.
Q2. What country is the richest in 1952 (far right on x axis)?
gapminder_1952 = subset(gapminder, year == 1952)
gapminder_1952 %>% top_n(1, gdpPercap)
## # A tibble: 1 x 6
## country continent year lifeExp pop gdpPercap
## <fct> <fct> <int> <dbl> <int> <dbl>
## 1 Kuwait Asia 1952 55.6 160000 108382.
Here it is evident that Kuwait was the richest country in 1952.
You can generate a similar plot for 2007 and compare the differences
ggplot(subset(gapminder, year == 2007), aes(gdpPercap, lifeExp, size = pop)) +
geom_point() +
scale_x_log10()
The black bubbles are a bit hard to read, the comparison would be easier with a bit more visual differentiation.
Q3. Can you differentiate the continents by color and fix the axis labels?
ggplot(subset(gapminder, year == 2007), aes(gdpPercap, lifeExp, size = pop, colour = continent)) +
geom_point() +
scale_x_discrete(name = "GPD Per Capita")+
scale_x_discrete(name = "Life Expectancy")+
scale_x_log10()
## Scale for 'x' is already present. Adding another scale for 'x', which will
## replace the existing scale.
## Scale for 'x' is already present. Adding another scale for 'x', which will
## replace the existing scale.
Q4. What are the five richest countries in the world in 2007?
gapminder_2007 = subset(gapminder, year == 2007)
gapminder_2007 %>% top_n(5, gdpPercap)
## # A tibble: 5 x 6
## country continent year lifeExp pop gdpPercap
## <fct> <fct> <int> <dbl> <int> <dbl>
## 1 Ireland Europe 2007 78.9 4109086 40676.
## 2 Kuwait Asia 2007 77.6 2505559 47307.
## 3 Norway Europe 2007 80.2 4627926 49357.
## 4 Singapore Asia 2007 80.0 4553009 47143.
## 5 United States Americas 2007 78.2 301139947 42952.
Here one can see that Ireland, Kuwait, Norway, Singapore and the United States were the five richest countries
The comparison would be easier if we had the two graphs together, animated. We have a lovely tool in R to do this: the gganimate package. And there are two ways of animating the gapminder ggplot.
The first step is to create the object-to-be-animated
anim <- ggplot(gapminder, aes(gdpPercap, lifeExp, size = pop)) +
geom_point() +
scale_x_log10() # convert x to log scale
anim
This plot collates all the points across time. The next step is to split it into years and animate it. This may take some time, depending on the processing power of your computer (and other things you are asking it to do). Beware that the animation might appear in the âViewerâ pane, not in this rmd preview. You need to knit the document to get the viz inside an html file.
anim + transition_states(year,
transition_length = 1,
state_length = 1)
Notice how the animation moves jerkily, âjumpingâ from one year to the next 12 times in total. This is a bit clunky, which is why itâs good we have another option.
This option smoothes the transition between different âframesâ, because it interpolates and adds transitional years where there are gaps in the timeseries data.
anim2 <- ggplot(gapminder, aes(gdpPercap, lifeExp, size = pop)) +
geom_point() +
scale_x_log10() + # convert x to log scale
transition_time(year)
anim2
The much smoother movement in Option 2 will be much more noticeable if you add a title to the chart, that will page through the years corresponding to each frame.
Q5 Can you add a title to one or both of the animations above that will change in sync with the animation? [hint: search labeling for transition_states() and transition_time() functions respectively]
anim3 = anim + transition_states(year, transition_length = 1, state_length = 1) +
labs(title = "Year: {closest_state}")
anim3
anim4 <- ggplot(gapminder, aes(gdpPercap, lifeExp, size = pop)) +
geom_point() +
scale_x_log10() + # convert x to log scale
transition_time(year) +
labs(title = "Year: {frame_time}")
anim4
Q6 Can you made the axesâ labels and units more readable? Consider expanding the abreviated lables as well as the scientific notation in the legend and x axis to whole numbers.[hint:search disabling scientific notation]
options(scipen=999)
anim5 = anim + transition_states(year, transition_length = 1, state_length = 1) +
labs(title = "Year: {closest_state}") +
xlab("GPD Per Capita")+
ylab("Life Expectancy")
anim5
anim6 <- ggplot(gapminder, aes(gdpPercap, lifeExp, size = pop)) +
geom_point() +
scale_x_log10() + # convert x to log scale
transition_time(year) +
labs(title = "Year: {frame_time}")+
xlab("GPD Per Capita")+
ylab("Life Expectancy")
anim6
Q7 Come up with a question you want to answer using the gapminder data and write it down. Then, create a data visualisation that answers the question and explain how your visualization answers the question. (Example: you wish to see what was mean life expectancy across the continents in the year you were born versus your parentsâ birth years). [hint: if you wish to have more data than is in the filtered gapminder, you can load either the gapminder_unfiltered dataset and download more at https://www.gapminder.org/data/ ]
My question is: How did the population of country colored by the continent evolve through time?
anim7 <- ggplot(gapminder, aes(year, pop, group = country, color = continent)) +
geom_line() +
scale_y_log10()+
transition_reveal(year)
anim7